Protective device for interlocking systems



Sept. 20, 1932. J. c. LINDNER 1,877,917

PROTECTIVE DEVICE FOR INTERLOCKING SYSTEMS Filed Aug. 15, 1950 2 Sheets-Sheet l Sept. 20, 1932. J c. LINDNER 1,877,917

I PROTECTIVEDEVICE FOR INTERLOCKING SYSTEMS Filed Aug. 15, 1930 2 Sheets-Sheet 2 FIG. 2.

INVENTOR yaezww ATTORN EY Patented Sept. 20, 1932 p .UNITIEDFSVTATESI PATENT OFFICE JOHN c. LINIDNER, or ROCHESTER, NEW YORK, AssIGNo T GENERAL RAILWAY SIG- NAL COMPANY, OF RocHEs'rE ,NEwYoRK description of the invention progresses.

PR0'riizo'rivn DEvIc' EoR.

Application filed August 15,

This invention relates to protective:devices for interlocking systems, and more particularly to means whereby interlocking systems are protected against improper op-' eration of the. traffic controlling devices, due to crosses between operatingwires and other derangements of wiring and connections. 7

In interlocking systems, the distant traffic controlling devices are usually operated electrically over control wires from the tower. To obviate the improper'operation of such'traffic controlling devices. as, signals, switches, derails, and thelike, due to crosses, shorts and grounds in the system, which would also'cause current to flowin a direction opposite to the normal current flow,- a relay is interposed, which is responsive only to reverse currentLand 'is'etfective to interrupt the main source of current. With the source of energy cut off from the device which the relay'protec'ts, the} device cannot again be operated until the relayis restored to its normal/position, and it is desirable inrestoring the relay to avoid forci bly holding the'control circuit closed in the event that an abnormalcondition still exists in the circuit.

One ofthe objects of the present invention is to provide a means for protecting a controlled device as described above, which will besimple as well as reliable in its'operation, with a'convenlent and safe means 01"? restoring the circuit after the operation In describing the-invention in detail, ref-.- erence will be made to the accompanying drawings, which are merely illustrative of the invention 'and are not intended inany manner in a limiting sense, and in which Fig. illustrates a typical switch controlling circuit, forming a part of an interlock ing system, and embodying the'present invention. Q r v t Fig. 2 is -a side elevation'of a protective device embodying-the present invention; andg- 3 is an, e d view-Q e dev e film .sidered." g, Referring to' Fig. 20f the accompany ng ment." V

In the controlling system, illustrated in Fig; 1, a switch machine SM, consisting of.

the motor armature M and field winding F,

with its accompanying pole changer, is

shown connectedto operate a track switch TS. This switch'machine is electrically, op-

erated andmaybe of any suitable construction such as shown in the patent to Howe N 0. 1,466,903 dated Sept. 4, 1923.

. The controlof' the switch machine SM is obtained by a control lever L of an inter locking system, which lever is mechanically interlocked with conflicting levers by atap- 7 petbar 25 o erated by a: roller 26- moving e contact arrangement the lever and the indication-latch mechanism operated by the indication coils IM and safety. coils S are shown, but willnotbe'described 1 in slot 27.

in detail, as they are of the type specifically described in the patent to Howe No. 1,163,154 dated Dec.'7, 1915. v r V The protective deviee P is shown protect ing'the switch machine SM as'controlled by lever L, and a second 'protective device I is shown to indicate the invention as applied to another similar switch machine and its corresponding'control lever, the latter being indicated merely by a dottedrectangle.

A cross indicator is conveniently shown as being a lamp I, and a restoring switch for all of the protective devices P P etc. in the system is represented by a self restoring push button switchR, which, when not actuated, makes contact at point 36, and when actuated, breaks this contact and makes contact at point 70. A source of electrical energy is conventionally represented by battery '13,

with the usual positive and negative busses and an additional indicator lamp bus (so designated) for the cross indicator circuit. 7

Before describing theoperation and tracing the circuit of this traflic controlling system, the construction of the protective device-included in this invention,- will be condrawings, the protective device embodying th presentinvention, as illustrated, includes large circular pole piece'th On the core 4" are provided coils 6 and 7 for purposes more clearly explained hereinafter. The free end of the permanent magnet M,

has secured thereto a triangular, orwedgeshaped, block 8 fastened in place by a bolt 9, and convelliently called a bearing block. It is of suitable material, such as tempered steel, to pIioVide a durable, frictionless, knife-edged bearing, for an armature 10. The armature 10 has its extreme right end bentup and then down, to fo'rmagroove fitting directly over well through either of thetwo extending theknitefledge portion ofibearing block-8,

the bearin-gcb'lock being provided with a" screw. 11passing .throughan oversized opening, inarmature, 10, withits head normal-1y, spaced from the armature itself. This holds the armature in; place in the event of. extreme jarsor .the'like, but does not olfer any re sistance to motion. of the armature about its pivotal knife edge support. s

Secured, to the armature 10 but electrically insulatedit'rom it, are two contacts 12 and 13 (see.-Fig.:.3.)l which are electrically connected to each otherby a strap 14. The armature 10,

pivoting about its linifevedge silipport' 8, is

Habit-3101601118 in contact with either the pole face51or the extension 1, and since both the' core 4 and the extension lare constructed of soft iron. themagnetic'fiux due to the permanent magnet-,M ordinarily passes equally members Thus, when'the armature 10 is against .eitherrof, these members, it makes thatpat-h of the lesserreluctance, and consequently. the armature stays in whichever position iit is placed.

The sof-t lI'QIlQXiJGIlSlOD 1 is recessed to receive altermina'l and contact mounting board 15, which carries two U-shaped contact tinge'rs 1;? held in place in groovesby terminal posts -16., ,,These contact fingers are provided with; suitable contacts 17 at theirfree ends,

onarmature 10. Anadjustment" means for thet yactive force on the armature in the nor- IDZLLOI' raised:pos1t1on,'1s'prov1ded by screw 18, conveniently called a residual pin, and

made; of some non magnetic material, which is threadedlinto extensionl and'islocked in V, an 'adjustedposition by a nut 19. By means ofthis, pin ,,the air gap in the fnormal magadjusting the sensitiveness of the device, for

115, to engage with contact 23 andlift it use! of Contact" 22, when said armature lifts the plunger 24 by moving, to its normal position. When armature 10 is released from its normal position, plunger 24 is allowed to drop, permitting contact 23' to engage with contact 22 through suitable low resistance points at their'free ends,

described,fwhen"used in such a circuitttas shown in Fig. 1'.

Assuming that the 'operatordesires to and also assuming. that its control leveris not locked by other conflicting control levers,- he pulls thelever'L unti'lfthe contact'blocksj 28; and: 29 engage with 'thereversecontacting springs '80 and 31, while further movement in the same direction ispreventedbecause 6f latcli 'bar' 32. "The leverL has now assumed the half. reverselpositi'on which "completes a circuit as follows beginning at the posi tive side [of batteryB, wires 33 and 34, self" restoring push button "switch'R, c'on't'actBG wire 37, positive bus,"wir"e 38,coils'of safety magnet 8, wire 39,contacti'fingerstl, con

tact 29, wire 40, reverse control wire RVV, contacts 41, movable contact42, wires 43 and 44, motor 'a-rmatu're M, wire'45, contacts46,

movable "Contact 47, wire '48,""moto'r "field" Winding F, common return wir'eC, wire 49, contacts 17, armature' 10, wires 50 "and 51," negative bus, Wire52, back to negative bat tery B. '1'

The completion of this 'circuit causes the switch machinemotorto operatein such a direction as tormove the. switch pointsto' the" reverse position, and at theicompletionof which are engageable by contacts 12 and 13;:

between the two fingers 54. 1 This movement prepares the motor for returning the switch to itsfn'ormal ,"pjosition upon return of the lever,as well as utilizes the dynamic energy Y of the revolving armatureto indicate that A the switch machinehas'perform'ed its func-v 1 netic circuit can be varied, thereby directl'yi' tion. The generation of this dynamidcur rent has a desirable snubbing action'onthe -motor.f #The direction in which this dynamic current flows in the" armature will depend on The operation of theswitch machine and the. application of unauthorized currentto certainv parts of theicircuit will now-be dis-1 cussed, to thus obtain. a clear understanding of the operation of the protective device just f but due to the fact that the armature is pole changed by movable contacts 42 and 47 its the direction of rotation of the armature,-

relative polarity with respect to the field is cuit, under'normal conditions, which is'as follows :beg1nn1ng at the armature of the motor M, wire 44, contact fingers 54, movable contact 47, wires 55 and 48, motor field 3 winding F, common wire C, wire 65, operat ingcoil 6 of protective device P wire 56,: indication magnet coils IM, wire 57, contact fingers of control lever L, contact 28, wire 2) by this current is in such-a directionasto 58, normal control wire NW, contact fingers 53 of pole changer, movable contact 42, wire 59, wire back to armature of the motor By looking "atFig. 2 it will be noticed that armature-10, having been placed in the normal position will remain there due to the fact that the major part ofthe flux is passing through extension 1,and through arma ture 10 to the permanent magnet Mg, there-f by attracting armature 10 to its raised posi- -tion against extension 1. The operating coil 6 is so arranged that current flowing in the normal direction through theindication' circuit, just traced, produces a fluxwhich' aids the passage of flux from thepermanenti magnet through the extension 1 andin this way produces a stronger attraction between levers, and a circuit is completed which is very similar to the reverse operating circuit the armature 10 and extension 1. This current flowing in the indication circuit-has the purpose of causing the armature'of indi cation magnet IM to be attracted, thus effecting operation of thelatch 60 which 019- erates latch bar 32, thereby unlocking the lever L to permit the operator to complete the stroke of this lever to a full reverse poesition, which stroke, when completed, unlocks certain other conflicting or associated levers. e

When theoperator desires to return the switch to its normal position he pushes the control lever L back to its normal position, providing it is not locked by conflicting already traced. The indicating'current will be received the same as 1n the reverse operatlon and in the same d1rect10n,-as heretofore described,'and its efl'ect on' the'indica-.

tion magnet 1M, and the will be identical. a r

- j However, in the event of an abnormal condition on the control wires orconnections such as across, 'a gground or short circuit of such a nature as to allow current to flow between control wires RWand NW, the

protective device current might tend to flowin the opposite direction and operate the indication magnet 'IM, if it were not for the action of the protective devicewhich is asfOllowsa-the current from battery B will flow through wires cation-magnet coils IM, wire 56, operating coil 6 of safety device-P ,wires and 49, 1 contacts '17, armature 10, wire 50, wire 51,

negative bus, wire 52', back to battery B.

' tion toreverse control wire RW, contact fin- 'gers 63, contact 28,- wires 64 and 57, indi- It will be noted that this is in a direction oppositeto' the normal flow of current through the operating coil of the protective device, andthefluxsetupin core 4 (see Fig.

aid the passage of fluxfrom the permanent magnet -Mg through the-core 4, depriving the extension '1 of'the maj'ors part of its flux, and decreasing the retaining force on the armature 10 to such an extent that it is both face '5. This breaks the circuit between the further operation of the'switchimachine un- -til theabnormalcondition has been remedied. -The armature-.dropping to its lower position will release plunger 24, allowing contact 23 to close on contact 22, closing a 'c ircuitfto cross indicating lamp I as fol- :lows beginning at battery B, wires '33 and 66, indicating lamp I, wire 67 indicator lamp bus, wire 68, contacts 22 and 23, wire's 69 and 51, negative bus,'wire 52- and back to battery The second protective device P with its switch machine -SM having connections NW RW? andC, together with its protective'relay P have been included to show protective devices, correspondingto. the number of devices tobe protected. j' I a WVhen the operating circuit is again to be restored, the operator actuates push buttons R," which opens the circuit of the positive battery to positive bus, therebyipreventing the operation of any device, while this'push button is in said actuated position.

Also,.th'e operation of push button R applies energy'to restoring coil 7 of the protective device, and this coil'is connected in series witli' the restoringcoils or all' ofthe attracted magnetically and by gravity to pole armature contact fingers 1'2 and 13, and the stationary cont-acts'17 which prevents they v the circuit arrangement for a plurality of protective devices in the system through the following circuit beginning"at battery B,

wires 33and 34, push button switch R, contact 70, wire 71, restorin'g-coilf7, wire 72'to negative bus, as indicated, by wire 73, and

7 is so arranged that the flux, produced by current flowing inthis circuit, opposes the flux inethe core 4 produced the permanent a plurality of restoring coils on the total :number of protective devices, returning to i in condition to -operate normally.

mally flows, as-;wel1 as to -close a circuit to coinloin'ation, an electrically operated traffic control, when energizing said restoring -magnet, and; strengthens theflugnin entensionwcontrolling device; a-isource ofi4-current.;.; an

,a-l toe ex nt fina i ing fliQi nt-ierce tonnperat-ingcircuit:forsaidatraflic controlling -;act oathe-armaturc 10 M aisevit romfi pole device-including a commomrrcturn *WfiIQ; a i face;5 to its nor nal positlon against eaten- 1; d n'amicindicatingcircuit-for said trafiicrconcn 5g 1f the;;QO- l c it-. sa-n w inits wt-roll ga 1 normabcondition, thearmature willremain return Wire; and across PIOtGCiFlOHwdGYlCG raised as the low-xeluotanceipath is. thIPQugha havingmagnetic :circuit inc-lud-ing an ar- -t l e-ar1nat;ure and extension, asfpneviously eX -;;-Inatu incans-ior actuatingsaid armature v zplai-ned and-the 'PUSh-ebLLt/tOII being :selt rea. ,yvhenfcurrentflows in an abnormal direction .storiliga.ilgaimiconnects ithe pOSlt1Vy- S1(1Q of, inrsaid :coI-nmon return ;W1I ;&Ild a -c1rcu1t v the battery to the positlvebus as :soon asthe ,!fQ-I-;I-QStQ I'1ng said armature to its-normal po -operato gireleases it. ;,-,Bi it;the circuit -istnevery sition waiters operationi inc1nding-.tl1e s aid l eldqolosed, as;lthe protectivendevice is in a wsource of energy; and a selfrestoring, Tpush -cond-ition to interrupt:the-circuit-theinstant .-.b ut,ton'switch. it isclo'sed by releasing pushibutton R,; The 3., In,- an-electri.c interlockingeystem; in a restoring of.theiprotectivedevicealsointer-1" -combination, an electricallyoperated switch ruptswthe cross-indicating lamp oircuit,..,machineyasource of-current; anoperating through contacts, 22 ,andQZ-B- thereby indicircuitiorz saidswitchimachine;.ia dynamic eatingto thesoperatorzthatthe circuit is again indicating circuit for said switoh inachine in p v ,cluding a cross protection-device, constructed A1?Bverse eurrent protective; device- -has v tojdistinctlylrespond tocurrent'flowing in an ,;thusbeenprovided whichis-adapted toopen abnorinaldirection in said indicating circuit -,a circuitif thecurrent in; .giiiencircuit flows toiassume an abnormal positionyelectroreii aflw Re s E d TQQt QH=tQ hfl- WhiGh-:it:J 0r-, ,sponsive restoringineans-iorsaid cross pro- 1 te ction- :levicerestoring it to itsnor-rnal 00113 vindicatethat an abnormaL condition exists: dition .said means ,disconnectingsaid source )Bi ovision is also,.madeionreclosing the 'cir-J' oii current-from. the operating circuits While @cuit interrup ed by-thedeVi ,.Withoutforcipplying said source of-furrenttofisaid-rebly holding the circuit closed whileidoingnsof. fsto ging meansi .icifid-embod ment (lithe: P12659111} inven i n,,,- electrically: operated traffic controlling.deaia d' ayi g OW-I it-appl ed t J LSL lglQ- -,Wice,including-a Inot0r;aasource oi -current; i litarrangemfi t, i s desired -heuunflel' v an operating circuit for said devicega dygst o rt att i has. been; 10 IP h-QQ FPO Q; ,namicindicating circuit; for said-device in- 0-f hQ'YY gh W QPh ilr fc f fi qm y be n: :clud inga crossprotection device having-- any plied, rather than lllustratlng 1ts scope or the armature included, in its magnetic circuit; i r struction iprefera yimpl yed in means-ion interrupting v said [operating cir- ,practice; and that Q- PQC fi QGQ 1T fi L cuit by theoperation oi said-armature; said l WI ssus epti l f'c n ide a e odifica-j:crossproieetion device including contacts controlling ,l system to which, the invention is applied? all without departing "from'the scope oi the invention onthe idea oflmeans,

underlying thesame- 45 J'Iavingthus dfiscribedmyinvcntion what 1- the operation of said armature-from its normal position and means in the circuit-completedby saidcontacts to: indicateithe convedition of the cross protection device. 5.;-In an interlocking system, in: combina- 1.313111 1 I -,-!,t ion,;;ai plurality of switchiinachines means 1 l rin nterlocklng system comprising, 111 -.1for ,-energizingsaid switch machines -levers c rn ln tl na 1} electrlca ly operated traffic for ;c on,tr01l ing said. switchmachineg; a plu- QO t 011. 9,d fi 1 wralityf of erossprotection relays forre's-peci Qp -T i g 61179-111? iorjsmii devlcfih'lI-lcllldmg tively protecting saidcswitch machines an cQntgmtsfiQn-tmned y e oithfl-lnter" e leetro-responsive restoring means fonareach V lo kl gu yfi em,fi mi l wp ll IP Q ofsaid cross protection relays, and ,a-single A returnmw ew; a. dynam c lndlcat g. rq manual-lyoperable reset-control foivener-g izfor sa d traffic controll ng;devlceilnclud ng ing an of Said reset means l 1 Qlf fi d- 9 9 r filg return :1 6.; In an: interlocking system, incombina- Y fl dt 1 l- T T Q cation, at-plurality of switch HlilOhiIlGS iQVBIS 1,.icct1on d6V1C8rWli3h aIl 21111121171118Included in )f L 0 1 h C 1 itsinagnetic v :irc1iit;,saicl source; oicurrent "j i'i O i 1W m Q i 3P beingdisconnected byathe operation oflis'aid l 1 10171 Fm? Orl rwpee armature to itsy abnormalflpgsitionLand an :tively protec ingsaid syvltch niach-lnes aneelec roeresppnsi e,a=manua11yr controllable Q FQ P Q i f Q m s fol each Iliesmringsaid'firmatm-g to itsfinop of said cross protectlon dev ces, and a'single t i manually operable reset control for energizall glggtrig 'int grlogking s y t em i ingall of said restoring means; said reset ISO device-including the said common :20 aHavingthusshown ai d described onetspe- A AnIinterlocking system rcomprising,an c

, oti n QQQdQPt fiheni lwfint fi O hepar iou ,held o en by said armature in its normal. mlnterlwk Systems d-v\p m ..rpositionand allowed to complete-a circuit by devices, an electro-responsive restoring means for each of said cross-protection devices, and

a single manually operable reset controlfor energizing all of said restoring means, said reset control, when energizing said restoring means, operating to deenergize said switch machines, and a single indicating means controlled by each of said cross protection devices.

8. In an interlocking system for railroads,

a switch machine, operating circuits for the switch machine for operating it to normal and reverse positions respectively, a control lever govermng sald operating circu ts, a protective device having contact means included in said operating circuits, means opening said contacts when abnormal current flows in said operating circuits, and electro-responsive means for closing said( ntacts. v r

9. In an interlocking system r'orrailroads, a switch machine having operating circuits, a control lever governing said operating circuits, a protective device having contacts and two windings for opening and'closing said contacts respectively, means including said contacts in said operating circuits, means energizing one of said-two windings for opening said operating circuits when abnormal current flows therein, a manually operable contact means for energizing the other of said two windings for closing said contacts, said manually operable contact means simultaneously opening said operating circuits, and means returning said manually operable contact means to normal to close said operating circuits if said contacts of said protective device are closed. I

10. In an interlocking a switch machine having operating circuits, a control lever governing said operating circuits, a protective device effective for opening said operating circuits'when abnormal current flows therein, said device having electro-responsive means for restoringsaid protective device to normal for closing said operating circuits, and contact means manually operable for actuating said electro-responsive 'means of said protective device and for simultaneously opemngsaid operat ng c1rcu1ts 1 only until said electro-responsive means ceases to be actuated.

11. In an interlocking system for railroads,

a switch machine having operating circuits of the dynamic indication type, apolarized cross protection relay included in said operating c1rcu1ts, sald'relay being responslve only to abnormalcurrent due to crosses, an electros system for railroads, I

cross protection relay, a self-restoring contact means for closing a circuit for saidelec tro-responsive restoring means and opening said operating circuits when actuated, said self-restoring contact means closing said operating circuits when not actuated.

12, In an interlocking system for railroads,

a switch machinehaving operating circuits of the dynamic indication type, a cross protection relay comprising a permanent magnet having two extensions of soft iron fastened to oneof its ends, two coils on one of said extensions, an armature p votally supported ,by the other end of said permanent magnet and operable to either of twopositions into contact with one or the other'of said two extensions, means including one of said coilsv in said operatingflcircuits in a manner that current flow due to normal operation of said switch machine actuates said armature to one of its two positions and abnormal current actuates said armature to the other ofits said two positions, contacts operated'by said armature and adapted to open said operating circuits when said armature isactuated by abnormal current, and means for energizing said other coil so as to actuate said armature to its said one position subsequent to actuation of said armature to its other position.

, 13. In an interlocking system for railroads, a switch machine, operating circuits for the. switch machine for operating it to normal and reverse positions respectively, a control lever governing said operating circuits, a protective device having contact means included in said operating circuits, means opening said contacts when abnormal current flows in said operating circuits, and manually controllable electro-responsive means for closing said contacts v In testimony whereof I afiix my signature. JOHN G. 'LINDNER.

responsive restoring means for said polarized 

